We can define the 4 states of No Post, No Power, No Video & No Boot as follows :

No Post (Power On Self Test)

Once the Power button is pressed, the system will go through a series of internal checks. If any of these checks should fail, the system will not boot to Windows and the diagnostic LED's and or Power button LED should illuminate to indicate the potential problem.

No Power

Once the Power button is pressed, no Diagnostics LED's will illuminate nor the Power button LED, the system will not boot to Windows and there will be no signs of power to the system, keyboard or mouse.

No Video

Once the Power button is pressed, the system will power on and proceed to the POST checks where you may see the Diagnostic LED's illuminate for a short period of time, the Power button LED will illuminate as well as the keyboard LED's but there will be no signs of video on the Screen/Display. You may hear the Windows login melody but the screen is blank.

No Boot

Once the system has loaded the Dell splash screen and then finished the POST checks, the Dell splash screen goes off and the system hands over to the Operating System. If the operating system doesn't start for any reason, this is called a No Boot.

The term POST refers to Power-On Self-Test, which is a series of checks the computer goes through whenever it starts. If the computer fails any of these tests, it will stop the start-up process and report a fault.

Indications of a failed POST include :

If the computer is displaying the Dell logo and does not move past that point, it has probably failed POST.

If the power indicator lights up and it is amber or orange, this is usually an indicator that it has failed POST.

If you see text on a black screen, the computer is currently performing the POST. If the computer stays in that condition and does not move past it, it has probably failed POST.

If the monitor displayed anything at all during the startup process but is now black, this probably indicates that the computer failed POST.

If the computer is beeping or if Diagnostic LEDs/Power LEDs are flashing, note down if there is a particular pattern in which it beeps or flashes and the colours seen.

If the computer is not beeping and the Diagnostic LEDs and caps/num/scroll lock LEDs are not flashing or lit, unplug all connections and remove all media communication devices (e.g. external monitors); reconnect one at a time and check if the computer functions.

Listed below you will see a table that gives both an error and the suggested troubleshooting for that error. In order to know what the error is on your PC, you will need to consult the diagnostic indicators built into your Dell computer.

Note: The diagnostic LEDs only serve as an indicator of the progress through the POST process. These LEDs do not indicate the problem that caused the POST routine to stop.

Unplug the computer. Allow one minute for the power to drain. Plug the computer into a working electrical outlet and press the power button.

Reseat all internal cables.

Replace system board.

A possible system board, power supply (PSU), or peripheral failure has occurred.

Power off computer, leaving the computer plugged in. Press and hold the power supply test button on the rear of the power supply unit. If the LED next to the switch illuminates, the problem may be with your system board.

If the LED next to the switch does not illuminate, disconnect all internal and external peripherals, and press and hold the power supply test button. If it illuminates, there could be a problem with a peripheral.

If the LED still does not illuminate, remove the PSU connections from the system board, then press and hold the power supply button. If it illuminates, there could be a problem with the system board.

If the LED still does not illuminate, the problem is probably with the power supply.

If available, install a verified working PSU and check if system completes POST.

No CPU present.

Reinstall the CPU and restart the system. If the computer still fails to boot, inspect the CPU socket for damage.

Install a verified working CPU. If the system still fails to boot with the same diagnostic indicators, the system board is likely to to be faulty.

Memory modules are detected, but a memory power failure has occurred.

If two or more memory modules are installed, remove the modules, then reinstall one module and restart the computer. If the computer starts normally, continue to install additional memory modules (one at a time) until you have identified a faulty module or reinstalled all modules without error. If only one memory module is installed, try moving it to a different DIMM connector and restart the computer.

If available, install verified working memory of the same type into your computer.

A possible CPU or system board failure has occurred.

Replace the CPU with a known good CPU. If the computer still fails to boot, inspect the CPU socket for damage.

If the system still fails to boot with the same diagnostic indicators, the system board is likely to to be faulty.

BIOS may be corrupt or missing.

The computer hardware is operating normally but the BIOS may be corrupt or missing.

If the system still fails to boot with the same diagnostic indicators, the system board is likely to to be faulty.

Memory modules are detected, but a memory failure has occurred.

If two or more memory modules are installed, remove the modules (see your service manual), then reinstall one module (see your service manual and restart the computer. If the computer starts normally, continue to install additional memory modules (one at a time) until you have identified a faulty module or reinstalled all modules without error.

If available, install working memory of the same type into your computer.

A possible graphics card failure has occurred.

Reseat any installed graphics cards.

If available, install a verified working graphics card into your computer.

A possible floppy drive or hard drive failure has occurred.

Reseat all power and data cables.

If available, replace cables with verified working cables.

If issue persists, replace Floppy Drive or Hard Drive with a verified working unit.

A possible USB failure has occurred.

Reinstall all USB devices and check all cable connections.

No memory modules are detected.

If two or more memory modules are installed, remove the modules (see your service manual), then reinstall one module (see your service manual) and restart the computer. If the computer starts normally, continue to install additional memory modules (one at a time) until you have identified a faulty module or reinstalled all modules without error.

If available, install working memory of the same type into your computer.

Memory modules are detected, but a memory configuration or compatibility error has occurred.

Ensure that no special requirements for memory module/connector placement exist.

Ensure that the memory you are using is supported by your computer.

A possible expansion card failure has occurred.

Determine if a conflict exists by removing an expansion card (not a graphics card) and restarting the computer.

If the problem persists, reinstall the card you removed, then remove a different card and restart the computer.

Repeat this process for each expansion card installed. If the computer starts normally, troubleshoot the last card removed from the computer for resource conflicts.

A possible system board resource and/or hardware failure has occurred.

Disconnect all internal and external peripherals, and restart the computer. If the computer boots, add the peripheral cards back one by one until you find the faulty one.

If the problem persists, the system board or a system board component is probably faulty.

Another failure has occurred.

Ensure that all hard drive and optical drive cables are properly connected to the system board.

If there is an error message on the screen identifying a problem with a device (such as the floppy drive or hard drive), check the device to make sure it is functioning properly.

If the operating system is attempting to boot from a device (such as the floppy drive or optical drive), check system setup to ensure the boot sequence is correct for the devices installed on your computer.

Listed below you will see a table that gives both an error and the suggested troubleshooting for that error. In order to know what the error is on your PC, you will need to consult the diagnostic indicators built into your Dell computer. You can find a guide to these indicators on the articles listed below :

Note: The diagnostic LEDs only serve as an indicator of the progress through the POST process. These LEDs do not indicate the problem that caused the POST routine to stop.

Problem Description

Suggested Resolution

The computer is either turned off or not receiving power.

Reseat the power cable in the power connector on the back of the computer and the electrical outlet.

Bypass power strips, power extension cables, and other power protection devices to verify that the computer turns on properly.

Ensure that any power strips being used are plugged into an electrical outlet and are turned on.

Ensure that the electrical outlet is working by testing it with another device.

Use a verified working Power cable.

Ensure that the main power cable and front panel cable are securely connected to the system board.

All power supply units include a self-test ability in an isolation mode. A test button and LED are on the side of the unit where the AC plug is located. Ensure the power cable is connected to the supply & Press the test button to test the PSU.

If the PSU LED does not illuminate, remove the PSU cables from the system board and test again. If the LED still does not illuminate when the test button is pressed, the PSU is possibly faulty.

If after removing the cables from the system board and the PSU LED illuminates, one of the attached devices or components could be faulty. Remove all attached components, reattach the PSU cables and using the PSU test button, install each component individually to test.

Listed below you will see a table that gives both an error and the suggested troubleshooting for that error. In order to know what the error is on your PC, you will need to consult the diagnostic indicators built into your Dell computer. You can find a guide to these indicators on the articles listed below :

The RTCRST jumper will allow you to clear NVRAM. The NVRAM will be cleared when the jumper is closed. (You can use the jumper from the password bridge.) Please remember that it is always best practice to remove the power cord from the PC before opening the lid or access panel and going inside. To properly clear the CMOS; AC power must be applied to the system for about 10 seconds while the jumper is closed. (This does not necessarily mean turning the computer on, putting power across the motherboard is enough.)

Pins 1-2 shorted clears NVRAM

WARNING: Resetting CMOS on this platform will clear the Management Engine BIOS Extension (MEBx) settings including the MEBx password and all configured settings.

Disconnect the external power from the PC.

Remove the computer cover.

Locate the 2-pin password connector (PSWD) on the system board.

Remove the 2-pin jumper plug.

Locate the 2-pin CMOS jumper (RTCRST) on the system board.

Move the 2-pin jumper plug from the PSWD pins onto the RTCRST pins for approximately 5 secs.

Dell Enhanced Pre-boot System Assessment, the ePSAs have been significantly improved with a view to streamlining the entire diagnostic process.

Note: These diagnostics have been included on many, but not ALL Desktop Systems.

During the boot process, the ePSAs are accessed from a cold boot by pressing the power button ON and repeatedly pressing the F12 key until the BIOS Boot Menu appears on the screen.

Use the keyboard up and down arrow keys to select Diagnostics on the menu and press the Enter key. ePSA begins by checking an area in system memory to insure it is safe and then loads itself into the verified memory area. ePSA then automatically begins high level algorithms on all system memory to insure integrity. ePSA next creates a graphical menu listing all discovered devices in the system.

Note: For further information on ePSA Diagnostics, please check out our :